U.S. patent application number 16/469302 was filed with the patent office on 2019-10-03 for grease composition, method for manufacturing grease composition, and method for using grease composition.
This patent application is currently assigned to IDEMITSU KOSAN CO., LTD.. The applicant listed for this patent is IDEMITSU KOSAN CO., LTD.. Invention is credited to Harutomo IKEDA, Asami KOGA, Hiroki SEKIGUCHI, Akihiro SHISHIKURA, Tomonobu TAKADA, Go WATANABE.
Application Number | 20190300814 16/469302 |
Document ID | / |
Family ID | 62909284 |
Filed Date | 2019-10-03 |
United States Patent
Application |
20190300814 |
Kind Code |
A1 |
SHISHIKURA; Akihiro ; et
al. |
October 3, 2019 |
GREASE COMPOSITION, METHOD FOR MANUFACTURING GREASE COMPOSITION,
AND METHOD FOR USING GREASE COMPOSITION
Abstract
Provided is a grease composition which is excellent in fire
extinguishing performance without water and can suppress fuming,
malodor, and liquefaction on burning and a method for producing the
grease composition. A grease composition contains a base oil (A), a
thickener (B), and a fire retardant (C), wherein the base oil (A)
contains a base oil (A1) having a 40.degree. C. kinematic viscosity
of 300 mm.sup.2/s or more, a sulfur content of 20 ppm by mass or
less, and an initial boiling point of 400.degree. C. or higher, the
fire retardant (C) is at least one of aluminum hydroxide (C1) and
1,3,5-triazine-1,3,5 (2H, 4H, 6H)-tris(ethanol) (C2), and a content
of the fire retardant (C) is 1.0 to 12.0 mass % based on a total
amount of the grease composition.
Inventors: |
SHISHIKURA; Akihiro;
(Chiba-shi, JP) ; TAKADA; Tomonobu; (Chiba-shi,
JP) ; SEKIGUCHI; Hiroki; (Ichihara-shi, JP) ;
KOGA; Asami; (Chiba-shi, JP) ; WATANABE; Go;
(Chiba-shi, JP) ; IKEDA; Harutomo; (Ichihara-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
IDEMITSU KOSAN CO., LTD. |
Chiyoda-ku |
|
JP |
|
|
Assignee: |
IDEMITSU KOSAN CO., LTD.
Chiyoda-ku
JP
|
Family ID: |
62909284 |
Appl. No.: |
16/469302 |
Filed: |
January 17, 2018 |
PCT Filed: |
January 17, 2018 |
PCT NO: |
PCT/JP2018/001244 |
371 Date: |
June 13, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10M 2207/1265 20130101;
C10M 125/10 20130101; C10N 2020/02 20130101; C10M 135/06 20130101;
C10N 2040/242 20200501; C10M 117/02 20130101; C10M 2203/1085
20130101; C10M 2219/024 20130101; C10M 169/06 20130101; C10N
2020/04 20130101; C10M 2207/1285 20130101; C10M 101/02 20130101;
C10M 129/08 20130101; C10M 169/00 20130101; C10M 2201/062 20130101;
C10M 133/42 20130101; C10M 2223/045 20130101; C10M 2215/30
20130101; C10N 2050/10 20130101; C10N 2030/06 20130101; C10M 117/06
20130101; C10M 2203/1006 20130101; C10M 2203/1025 20130101; C10M
2207/1236 20130101; C10M 2215/222 20130101; C10N 2030/40 20200501;
C10N 2030/50 20200501; C10N 2040/246 20200501; C10N 2020/06
20130101; C10N 2040/24 20130101; C10M 141/06 20130101; C10M
2207/022 20130101; C10N 2030/43 20200501; C10M 2207/1285 20130101;
C10N 2010/02 20130101; C10M 2201/062 20130101; C10N 2010/04
20130101; C10M 2223/045 20130101; C10N 2010/04 20130101 |
International
Class: |
C10M 169/00 20060101
C10M169/00; C10M 101/02 20060101 C10M101/02; C10M 125/10 20060101
C10M125/10; C10M 133/42 20060101 C10M133/42; C10M 129/08 20060101
C10M129/08; C10M 117/06 20060101 C10M117/06; C10M 117/02 20060101
C10M117/02; C10M 141/06 20060101 C10M141/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 18, 2017 |
JP |
2017-006937 |
Claims
1. A grease composition comprising a base oil (A), a thickener (B),
and a fire retardant (C), wherein the base oil (A) contains a base
oil (A1) having a 40.degree. C. kinematic viscosity of 300
mm.sup.2/s or more, a sulfur content of 20 ppm by mass or less, and
an initial boiling point of 400.degree. C. or higher, the fire
retardant (C) is at least one of aluminum hydroxide (C1) and
1,3,5-triazine-1,3,5 (2H, 4H, 6H)-tris(ethanol) (C2), and a content
of the fire retardant (C) is from 1.0 to 12.0 mass % based on a
total amount of the grease composition.
2. The grease composition according to claim 1, wherein a content
of the base oil (A1) is 80 mass % or more based on a total amount
of the base oil (A).
3. The grease composition according to claim 2, wherein the base
oil (A1) has a 40.degree. C. kinematic viscosity of 300 to 1,000
mm.sup.2/s.
4. The grease composition according to claim 1, wherein the base
oil (A1) is a bright stock.
5. The grease composition according to claim 1, wherein the
thickener (B) is a soap-based thickener.
6. The grease composition according to claim 1, wherein the fire
retardant (C) includes the aluminum hydroxide (C1) having has an
average particle diameter of 5.0 .mu.m or less.
7. The grease composition according to claim 1, further comprising
one or more retardant promotors (D) selected from zinc carbonate
(D1), polyhydric alcohol (D2), and sulfurized fats or fatty oils
(D3).
8. The grease composition according to claim 1, wherein a water
content of the grease composition is less than 1.0 mass % based on
the total amount of the grease composition.
9. The grease composition according to claim 1, wherein the sulfur
content of the grease composition is less than 2.0 mass % based on
the total amount of the grease composition.
10. A grease composition, for steel manufacturing equipment,
forging equipment, or a heat treatment apparatus, comprising the
grease composition according to claim 1.
11. A method for producing a grease composition, comprising the
following steps (1) and (2): (1) a step of mixing a base oil (A)
containing a base oil (A1) having a 40.degree. C. kinematic
viscosity of 300 mm.sup.2/s or more, a sulfur content of 20 ppm by
mass or less, and an initial boiling point of 400.degree. C. or
higher with a thickener (B) to form a grease; and (2) step of
mixing the grease with at least one of aluminum hydroxide (C1) and
1,3,5-triazine-1,3,5 (2H, 4H, 6H)-tris(ethanol) (C2) as a fire
retardant (C), after the step (1)to obtain a grease composition in
which a content of the fire retardant (C) is from 1.0 to 12.0 mass
% based on a total amount of the grease composition.
12. Use of the grease composition according to claim 1 as a grease
composition for steel manufacturing equipment, a forging equipment,
or a heat treatment apparatus.
Description
TECHNICAL FIELD
[0001] The present invention relates to a grease composition, a
method for producing the grease composition, and a method for using
the grease composition.
BACKGROUND ART
[0002] In various equipment and machines, grease may be used for
improving lubricity of a lubrication portion such as a bearing, a
sliding portion, and a joint portion.
[0003] A use environment of the grease varies greatly depending on
uses. For example, since steel manufacturing equipment and forging
equipment are exposed to a high temperature, the grease may drip
down and accumulate. When a high temperature manufactured product
or a scale scatters onto the accumulated grease, the grease ignites
and causes a fire, which is viewed as a problem. The scale is a
kind of iron oxide generated when iron is heated to a high
temperature.
[0004] In addition, when the grease accumulates in a narrow place
where a person's hand cannot reach, there is a problem that it is
difficult to remove the grease at any time.
[0005] Further, there is also a problem that it becomes difficult
to discover a fire early along with automation of equipment in
recent years.
[0006] Therefore, there is a demand for a lubricating grease
composition excellent in fire extinguishing performance that
prevents spread of the fire. For example, techniques of PTLs 1 to 2
are proposed for greases for the purpose of improving fire
extinguishing performance.
CITATION LIST
Patent Literature
[0007] PTL 1: JP 2011-105828 A
[0008] PTL 2: JP 8-199183 A
SUMMARY OF INVENTION
Technical Problem
[0009] PTL 1 discloses a grease composition containing a sulfurized
olefin, and discloses that in a grease burning test, the grease
composition ignites after a steel ball heated to 950.degree. C. is
put in, and then extinguishes fire (burning time: 125 to 200
seconds).
[0010] However, the grease composition of PTL 1 has a risk of
burning over a long time after ignition, and when the grease
composition is burned, there is a problem that the grease
composition liquefied by burning scatters around and contaminates
the surrounding environment while black smoke and malodor are
generated.
[0011] PTL 2 discloses a grease composition in which 30 to 100
parts by weight of water, 0.5 to 100 parts by weight of an
emulsifier, and 40 to 300 parts by weight of aluminum hydroxide are
blended with respect to 100 parts by weight of a base oil.
[0012] However, since the grease composition of PTL 2 is an
emulsion-based grease composition containing water, there is a
problem that rust occurs in equipment and machines clue to an
influence of water.
[0013] The present invention has been made to solve the above
problems, and an object of the present invention is to provide a
grease composition which is excellent in fire extinguishing
performance without water and can suppress fuming, malodor, and
liquefaction on burning, a method for producing the grease
composition, and a method for using the grease composition.
Solution to Problem
[0014] The present invention provides a grease composition, a
method for producing the grease composition, and a method for using
the grease composition of the following[1] to [3]. [0015] [1] A
grease composition containing base oil (A), a thickener (B), and a
fire retardant (C), wherein the base oil (A) contains a base oil
(A1) having a 40.degree. C. kinematic viscosity of 300 mm.sup.2/s
or more, a sulfur content of 20 ppm by mass or less, and an initial
boiling point of 400.degree. C. or higher, the fire retardant (C)
is at least one of aluminum hydroxide (C1) and 1,3,5-triazine-1,3,5
(2H, 4H, 6H)-tris(ethanol) (C2), and a content of the fire
retardant (C) is from 1.0 to 12.0 mass % based on a total amount of
the grease composition. [0016] [2] A method for producing a grease
composition, including the following steps (1) and (2):
[0017] (1) a step of mixing a base oil (A) containing a base oil
(A1) having a 40.degree. C. kinematic viscosity of 300 mm.sup.2/s
or more, a sulfur content of 20 ppm by mass or less, and an initial
boiling point of 400.degree. C. or higher with a thickener (B) to
form a grease; and
[0018] (2) a step of mixing the grease with at least one of
aluminum hydroxide (C1) and 1,3,5-triazine-1,3,5 (2H, 4H,
6H)-tris(ethanol) (C2) as a fire retardant (C) after the step (1)
to obtain a grease composition in which a content of the fire
retardant (C) is from 1.0 to 12.0 mass % based on a total amount of
the grease composition. [0019] [3] Use of the grease composition
according to the above[1] as a grease composition for steel
manufacturing equipment, forging equipment, or a heat treatment
apparatus.
Advantageous Effects of Invention
[0020] The grease composition of the present invention is excellent
in fire extinguishing performance without water and can suppress
fuming, malodor, and liquefaction on burning. In the method for
producing the grease composition of the present invention, the
grease composition exhibiting the above effects can be easily
produced.
DESCRIPTION OF EMBODIMENTS
[Grease Composition]
[0021] A grease composition of the present embodiment contains a
base oil (A), a thickener (B), and a fire retardant (C), wherein
the base oil (A) contains a base oil (A1) having a 40.degree. C.
kinematic viscosity of 300 mm.sup.2/s or more, a sulfur content of
20 ppm by mass or less, and an initial boiling point of 400.degree.
C. or higher, the fire retardant (C) is at least one of aluminum
hydroxide (C1) and 1,3,5-triazine-1,3,5 (2H, 4H, 6H)-tris(ethanol)
(C2), and a content of the fire retardant (C) is 1.0 to 12.0 mass %
based on a total amount of the grease composition.
<Base Oil (A)>
[0022] The base oil (A) contains a base oil (A1) having a
40.degree. C. kinematic viscosity of 300 mm.sup.2/s or more, a
sulfur content of 20 ppm by mass or less, and an initial boiling
point of 400.degree. C. or higher.
[0023] When the 40.degree. C. kinematic viscosity of the base oil
(A1) is less than 300 mm.sup.2/s, the grease composition is easily
burned and the fire extinguishing performance is insufficient. When
the sulfur content of the base oil (A1) is more than 20 ppm by
mass, fuming and black smoke on burning cannot be suppressed. When
the initial boiling point of the base oil (A1) is less than
400.degree. C., the fire extinguishing performance is
insufficient.
[0024] In the present specification, the "fire extinguishing
performance" refers to performance of extinguishing fire in a short
time without taking an operation for extinguishing fire.
[0025] When the 40.degree. C. kinematic viscosity of the base oil
(A1) is too large, the flowability tends to deteriorate. The
40.degree. C. kinematic viscosity of the base oil (A1) is
preferably 300 to 1,000 mm.sup.2/s, more preferably 350 to 800
mm.sup.2/s, and further preferably 350 to 600 mm.sup.2/s in view of
balance of improvement of fire extinguishing performance and
flowability.
[0026] In the present embodiment, the 40.degree. C. kinematic
viscosity and a viscosity index show values measured according to
JIS K2283: 2000.
[0027] The sulfur content of the base oil (A1) is preferably 10 ppm
by mass or less, more preferably 5 ppm by mass or less, and further
preferably 3 ppm by mass or less.
[0028] In the present embodiment, the sulfur content of the base
oil shows a value measured according to an ultraviolet fluorescence
method of JIS K2541-6.
[0029] When the initial boiling point of the base oil (A1) is too
large, the flowability tends to deteriorate. The initial boiling
point of the base oil (A1) is preferably 400.degree. C. to
600.degree. C., more preferably 420.degree. C. to 550.degree. C.,
and further preferably 430.degree. C. to 500.degree. C. in view of
balance of fire extinguishing performance and flowability.
[0030] In the present embodiment, the initial boiling point shows a
value measured under conditions of a pressure of 133 Pa according
to a reduced-pressure method of JIS K2254.
[0031] The base oil (A1) is not particularly limited as long as it
has a 40.degree. C. kinematic viscosity, a sulfur content, and an
initial boiling point within the above ranges, and one or more
selected from a mineral oil and/or a synthetic oil can be used.
[0032] Examples of the mineral oil of the base oil (A1) include a
bright stock.
[0033] The bright stock refers to a high viscosity base oil
produced through a treatment selected from solvent deasphalting,
solvent extraction, solvent dewaxing, and hydrofining on a
reduced-pressure distillation residue oil of a crude oil. The crude
oil for producing the bright stock can be used without a particular
limit, and examples thereof include a paraffinic crude oil and a
naphthenic crude oil.
[0034] Examples of the bright stock used in the present embodiment
include a bright stock (A1-a) obtained through hydrofining and a
bright stock (A1-b) obtained through solvent refining.
[0035] Examples of the bright stock (A1-a) include those obtained
by hydrofining the reduced-pressure distillation residue oil of the
crude oil. In addition to the hydrofining treatment, the bright
stock (A1-a) may be produced by appropriately combining
conventionally known refining processes such as dewaxing and
deasphalting.
[0036] Here, the hydrofining treatment refers to a hydrofining
treatment under relatively severe conditions under which (1) an
opening ring and dealkylation of a side chain of a polycyclic
compound due to hydrogenolysis, (2) isomerization, (3) removal of a
hetero atom from a hydrocarbon containing the hetero atom, or the
like occurs.
[0037] Examples of the bright stock (A1-b) include those obtained
by subjecting the reduced-pressure distillation residue oil of the
crude oil to a solvent extraction treatment. In addition to the
solvent extraction treatment, the bright stock (A1-b) may be
produced by appropriately combining conventionally known refining
processes such as a dewaxing treatment, a deasphalting treatment,
and hydrofinishing.
[0038] Here, the hydrofinishing is performed generally by
performing a hydrogenation treatment at a relatively low pressure
for the purpose of improving hue and the like, and is different
from the hydrofining treatment.
[0039] The mineral oil of the base oil (A1) of the present
embodiment is preferably the bright stock (A1-a) obtained through
hydrofining in view of producing a base oil having a 40.degree. C.
kinematic viscosity of mm.sup.2/s or more, a sulfur content of 20
ppm by mass or less, and an initial boiling point of 400.degree. C.
or higher. The bright stock (A1-a) obtained through the hydrofining
is also effective even in terms of raising a flash point.
[0040] Examples of the synthetic oil of the base oil (A1) include a
hydrocarbon-based synthetic oil and an ether-based synthetic oil.
Examples of the hydrocarbon-based synthetic oil include an a-olefin
oligomer such as polybutene, polyisobutylene, a 1-octene oligomer,
a 1-decene oligomer, and an ethylene-propylene copolymer, or a
hydrogenated product thereof, an alkylbenzene, and an
alkylnaphthalene. Examples of the ether-based synthetic oil include
a polyoxy alkylene glycol and a polyphenyl ether.
[0041] The base oil (A1) preferably has a viscosity index of 80 or
more, more preferably 90 or more, and further preferably 100 or
more. By setting the viscosity index of the base oil (A1) to 80 or
more, lubricity can be maintained in a wide range of
temperature.
[0042] The base oil (A1) preferably has a flash point of
200.degree. C. or higher, more preferably 250.degree. C. or higher,
and further preferably 270.degree. C. or higher in view of flame
retardancy.
[0043] In the present embodiment, the flash point shows a value
measured according to a Cleveland open-cup method of JIS K2265-4:
2007.
[0044] The base oil (A) may contain a base oil other than the base
oil (A1) described above.
[0045] From the viewpoint of making it easy to express effects of
the present embodiment, the base oil (A1) is contained in
preferably 80 mass % or more, more preferably 90 mass % or more,
further preferably 95 mass % or more, and most preferably 100 mass
% based on a total amount of the base oil (A).
[0046] A content of the base oil (A) in the grease composition is
preferably 50 to 98 mass %, more preferably 60 to 95 mass %, and
further preferably 70 to 90 mass % based on a total amount of the
grease composition from the viewpoint of making it easy to express
the effects of the present embodiment.
<Thickener (B)>
[0047] As the thickener (B), one or more kinds selected from a
non-soap-based thickener such as a urea-based thickener, a fluorine
resin-based thickener, and a carbon-based thickener, a soap-based
thickener, and the like can be used. Among them, the soap-based
thickener is preferable in view of flame retardancy.
[0048] Examples of the soap-based thickener include a single soap
such as a lithium soap, a calcium soap, and an aluminum soap, and a
complex soap such as a lithium complex soap, a calcium complex
soap, and an aluminum complex soap. Among them, the lithium soap
and the lithium complex soap are suitable in view of water
resistance and heat resistance.
[0049] The soap-based thickener can be obtained, for example, by
saponifying a carboxylic acid or an ester thereof with a metal
hydroxide as raw materials.
[0050] The soap-based thickener may be saponified in the base oil
(A) by adding a carboxylic acid or an ester thereof and a metal
hydroxide to the base oil (A).
[0051] Examples of metal constituting the metal hydroxide include
sodium, calcium, lithium, and aluminum.
[0052] Examples of the carboxylic acid include a crude fatty acid
obtained by hydrolyzing fats or fatty oils and removing glycerin, a
monocarboxylic acid such as stearic acid, a monohydroxy carboxylic
acid such as 12-hydroxy stearic acid, a dibasic acid such as
azelaic acid, and an aromatic carboxylic acid such as terephthalic
acid, salicylic acid, and benzoic acid. These may be used in one
kind alone or in combination of two or more kinds thereof.
[0053] In the present specification, the complex soap refers to a
soap obtained by using a fatty acid such as stearic acid, oleic
acid, and palmitic acid and/or a hydroxy fatty acid having 12 to 24
carbon atoms and one or more hydroxy groups in the molecule
(carboxylic acid A), and an aromatic carboxylic acid and/or an
aliphatic dicarboxylic acid having 2 to 12 carbon atoms (carboxylic
acid B) in combination as a carboxylic acid.
[0054] The soap-based thickener is preferably a single soap or a
complex soap containing a hydroxy carboxylic acid having 12 to 24
carbon atoms, more preferably a single soap or a complex soap
containing a hydroxy carboxylic acid having 16 to 20 carbon atoms,
and further preferably a single soap or a complex soap containing
12-hydroxy stearic acid as a raw material carboxylic acid.
[0055] In a case of the complex soap, it is preferable to use an
aromatic carboxylic acid and/or an aliphatic dicarboxylic acid
having 2 to 12 carbon atoms in addition to the hydroxy carboxylic
acid having 12 to 24 carbon atoms as the raw material carboxylic
acid.
[0056] Examples of the aromatic carboxylic acid include benzoic
acid, phthalic acid, isophthalic acid, terephthalic acid,
trimellitic acid, pyromellitic acid, salicylic acid, and
p-hydroxybenzoic acid.
[0057] Examples of the aliphatic dicarboxylic acid having 2 to 12
carbon atoms include azelaic acid, sebacic acid, oxalic acid,
malonic acid, succinic acid, adipic acid, pimelic acid, suberic
acid, undecanedioic acid, and dodecanedioic acid.
[0058] Among the exemplified aromatic carboxylic acid and/or the
aliphatic dicarboxylic acid having 2 to 12 carbon atoms, azelaic
acid is suitable.
[0059] A content of the soap-based thickener is preferably 80 mass
% or more, more preferably 90 mass % or more, further preferably 95
mass % or more, and most preferably 100 mass % based on a total
amount of the thickener (B).
[0060] A content of the thickener (B) in the grease composition is
preferably 1 to 10 mass %, more preferably 1 to 8 mass %, and
further preferably 2 to 7 mass % based on a total amount of the
grease composition.
[0061] By setting the content of the thickener (B) to the above
range, lubricity and handleability of the grease composition can be
easily improved.
<Fire Retardant (C)>
[0062] The grease composition of the present embodiment further
contains at least one fire retardant (C) selected from aluminum
hydroxide (C1) and 1,3,5-triazine-1,3,5 (2H, 4H, 6H)-tris(ethanol)
(C2).
[0063] Since at least one fire retardant (C) selected from aluminum
hydroxide (C1) and 1,3,5-triazine-1,3,5 (2H, 4H, 6H)-tris(ethanol)
(C2) is contained, it is possible to provide a grease composition
that puts out fire in a short time without performing an operation
for extinguishing fire in a case of ignition, and the fire
extinguishing performance is thus improved. Therefore, even when
the grease composition ignites, the grease composition of the
present embodiment can suppress the occurrence of fire.
[0064] In addition, since the grease composition of the present
embodiment contains at least one of the above (C1) and (C2) and has
an excellent fire extinguishing performance, it is possible to
suppress fuming, malodor, and liquefaction of the grease
composition, which originate in burning
[0065] Further, the above (C1) and (C2) do not contain sulfur which
is a main cause of the malodor. Therefore, the grease composition
of the present embodiment is extremely excellent in suppressing
malodor originating in burning.
[0066] The grease composition of the present embodiment contains
1.0 to 12.0 mass % of the fire retardant (C) based on a total
amount of the grease composition.
[0067] When the content of the fire retardant (C) is less than 1.0
mass % based on the total amount of the grease composition, the
fire extinguishing performance of the grease composition is
insufficient, and a fire cannot be suppressed.
[0068] When the content of the fire retardant (C) exceeds 12.0 mass
% based on the total amount of the grease composition, the fire
extinguishing performance corresponding to the content of the fire
retardant (C) cannot be expected and the content of the base oil
(A) and the content of the thickener (B) are relatively reduced, so
that lubricity is reduced. When the content of the aluminum
hydroxide (C1) exceeds 12.0 mass % based on the total amount of the
grease composition, the lubricity becomes too insufficient and
abrasion of a lubrication portion becomes intense, while
flowability of the grease composition is reduced and a pipe is
easily clogged. In addition, when the content of
1,3,5-triazine-1,3,5 (2H, 4H, 6H)-tris(ethanol) (C2) exceeds 12.0
mass % based on the total amount of the grease composition,
lubricity is reduced and an amount of a nitrogen compound generated
on burning increases with an increase of an amount of (C2), and a
malodor originating in the nitrogen compound becomes a problem.
[0069] The content of the fire retardant (C) is preferably 2.0 to
11.0 mass %, more preferably 3.0 to 10.5 mass %, and further
preferably 4.0 to 10.0 mass % based on the total amount of the
grease composition.
[0070] The content of the fire retardant (C) means the content of
the (C1) alone when the fire retardant (C) only contains the (C1),
means the content of the (C2) alone when the fire retardant (C)
only contains the (C2), and means a sum of the content of the (C1)
and the (C2) when the fire retardant (C) contains the (C1) and the
(C2).
[0071] An average particle diameter of the aluminum hydroxide (C1)
is preferably 5.0 .mu.m or less, more preferably 3.0 .mu.m or less,
and further preferably 2.0 .mu.m or less. By setting the average
particle diameter of the aluminum hydroxide (C1) to 5.0 .mu.m or
less, the fire extinguishing performance and the flowability of the
grease composition can be improved. A lower limit of the average
particle diameter of the aluminum hydroxide (C1) is not
particularly limited, but is generally about 0.01 .mu.m.
[0072] In the present specification, the average particle diameter
is a 50% particle diameter (d50: median diameter) in the case where
aluminum hydroxide particles dispersed in a solution are measured
by a dynamic light scattering method and a particle diameter
distribution is expressed by a cumulative distribution in terms of
volume.
<Fire Retardant Promotor (D)>
[0073] The grease composition of the present embodiment may further
contain a fire retardant promotor (D).
[0074] Examples of the fire retardant promotor (D) include one or
more kinds selected from zinc carbonate (D1), polyhydric alcohol
(D2), sulfurized fats or fatty oils (D3), and melamine cyanurate,
and one or more kinds selected from zinc carbonate (D1), polyhydric
alcohol (D2), and sulfurized fats or fatty oils (D3) are
preferable.
[0075] The zinc carbonate (D1) is an abbreviation of basic zinc
carbonate and is a compound represented by a chemical formula
2ZnCO.sub.3.3 Zn(OH).sub.2.H.sub.2O.
[0076] Examples of the polyhydric alcohol (D2) include glycerin,
trimethylolethane, trimethylolpropane, and pentaerythritol. Among
them, glycerin is preferable.
[0077] Examples of the sulfurized fats or fatty oils (D3) include
those obtained by sulfurizing animal and vegetable fats or fatty
oils such as beef tallow and soybean oil; unsaturated fatty acid
such as oleic acid, linoleic acid, linolenic acid, or a fatty acid
extracted from animal and vegetable fats or fatty oils; unsaturated
fatty acid ester obtained by reacting these unsaturated fatty acids
with various alcohols and acid chlorides; and mixtures thereof in
an arbitrary method, and sulfurized olefins.
[0078] The content of the fire retardant promotor (D) is preferably
1.0 to 10.0 mass %, more preferably 1.0 to 8.0 mass %, and further
preferably 2.0 to 7.0 mass % based on the total amount of the
grease composition.
<Additive (E)>
[0079] The grease composition of the present embodiment may contain
an additive (E) which can be selected from those blended in general
greases.
[0080] Examples of such an additive include an antioxidant, a rust
inhibitor, an extreme pressure agent, a thickener, a solid
lubricant, a detergent dispersant, a corrosion inhibitor, and a
metal deactivator, and one or more kinds thereof can be used.
[0081] Examples of the antioxidant include an amine-based
antioxidant such as alkylated diphenylamine,
phenyl-oc-naphthylamine, and alkylated oc-naphthylamine; and a
phenol-based antioxidant such as 2,6-di-t-butyl-4-methylphenol and
4,4'-methylene bis(2,6-di-t-butylphenol).
[0082] Examples of the rust inhibitor include a sorbitan fatty acid
ester and an amine compound.
[0083] Examples of the extreme pressure agent include a
phosphorus-based compound and a sulfur and phosphorus based
compound.
[0084] Examples of the thickener include polymethacrylate (PMA), an
olefin copolymer (OCP), polyalkylstyrene (PAS), and a styrene-diene
copolymer (SCP).
[0085] Examples of the solid lubricant include polyimide.
[0086] Examples of the detergent dispersant include an ashless
dispersant such as succinimide and boron-based succinimide.
[0087] Examples of the corrosion inhibitor include a
benzotriazole-based compound and a thiazole compound.
[0088] Examples of the metal deactivator include a
benzotriazole-based compound.
[0089] The content of each additive in the grease composition is
generally 0 to 10 mass %, preferably 0 to 7 mass %, more preferably
0 to 5 mass %, and more further preferably 0 to 2 mass % based on
the total amount of the grease composition.
<Water Content>
[0090] In the present embodiment, a water content of the grease
composition is preferably less than 1.0 mass %, more preferably
less than 0.1 mass %, and further preferably less than 0.01 mass %
based on the total amount of the grease composition.
[0091] By setting the water content of the grease composition to
less than 1.0 mass %, it is possible to easily suppress rust from
occurring on equipment and machines due to an influence of water.
In addition, since the grease composition of the present embodiment
uses the specific base oil and the specific fire retardant, it is
possible to improve the fire extinguishing performance even without
water.
<Sulfur Content>
[0092] In the present embodiment, the sulfur content of the grease
composition is preferably less than 2.0 mass %, more preferably
less than 1.0 mass %, and further preferably less than 0.5 mass %
based on the total amount of the grease composition.
[0093] By setting the sulfur content of the grease composition to
less than 2.0 mass %, malodor on burning can be easily
suppressed.
[0094] The sulfur content of the grease composition can be measured
according to ASTM D4951.
<Use of Grease Composition (Method of Using Grease
Composition)>
[0095] The grease composition of the present embodiment can be used
as the grease composition for various equipment and machines, and
is particularly suitably used as the grease composition for steel
manufacturing equipment, forging equipment, or a heat treatment
apparatus in which fire extinguishing performance is important.
[0096] The heat treatment apparatus refers to an apparatus used for
a heat treatment such as quenching, tempering, annealing, and
normalizing.
[Method for Producing Grease Composition]
[0097] A method for producing the grease composition of the present
embodiment includes the following steps (1) and (2): [0098] (1) a
step of mixing a base oil (A) containing a base oil (A1) having a
40.degree. C. kinematic viscosity of 300 mm.sup.2/s or more, a
sulfur content of 20 ppm by mass or less, and an initial boiling
point of 400.degree. C. or higher with a thickener (B) to thereby
form a grease; and [0099] (2) a step of mixing the grease with at
least one of aluminum hydroxide (C1) and 1,3,5-triazine-1,3,5 (2H,
4H, 6H)-tris(ethanol) (C2) as a fire retardant (C) after the step
(1) to thereby obtain a grease composition in which a content of
the fire retardant (C) is 1.0 to 12.5 mass % based on a total
amount of the grease composition.
[0100] The thickener (B) may be synthesized during the step (1).
For example, the thickener (B) may be obtained by adding a
carboxylic acid and a metal hydroxide to the base oil (A), thereby
causing saponification in the base oil (A).
[0101] In the step (1), the base oil (A) and the carboxylic acid
are preferably heated and dissolved at 80.degree. C. to 110.degree.
C. by stirring using a stirring blade or the like. After that, it
is preferable to add a hydroxide and heat them to 150.degree. C. to
200.degree. C. to mix them. At this time, it is preferable to hold
for 1 to 30 minutes.
[0102] The base oil (A) and the thickener (B) are mixed
sufficiently, and subsequently the resulting mixture is preferably
cooled to 120.degree. C. to 160.degree. C., and then cooled to
80.degree. C. to 110.degree. C. at 30.degree. C. to 60.degree.
C./hour.
[0103] In the step (1), the above-described additive (E) may be
further mixed. .
[0104] In the step (2), it is preferable to sufficiently mix the
composition obtained in the step (1) and the fire retardant (C) by
stirring using a stirring blade or the like.
[0105] In the step (2), the above-described additive (E) may be
mixed with the fire retardant (C).
EXAMPLES
[0106] Next, the present invention will be described in more detail
by Examples, but the present invention is not limited at all by the
Examples.
1. Measurement and Evaluation
[0107] Grease compositions of Examples and Comparative Examples and
raw materials of these grease compositions were subjected to the
following measurement and evaluation. The results are shown in
Tables 1 and 2. 1-1. 40.degree. C. kinematic viscosity, viscosity
index, sulfur content, initial boiling point, and flash point of
base oil
[0108] With respect to the base oils 1 to 3 used in Examples and
Comparative Examples, the 40.degree. C. kinematic viscosity and the
viscosity index were measured according to JIS K2283: 2000, the
sulfur content was measured according to a ultraviolet fluorescence
method of JIS K2541-6, an initial boiling point was measured under
a pressure of 133 Pa according to an reduced-pressure method of JIS
K2254, and a flash point was measured according to a Cleveland
open-cup method of JIS K2265-4: 2007.
1-2. Fire Extinguishing Performance, Fuming, Malodor, and
Liquefaction
<Fire Extinguishing Performance>
[0109] 70 g of the grease composition was put in a metal
cylindrical vessel having a diameter of 16 cm and a height of 3 cm,
and the surface was leveled evenly. A disc-shaped metal piece
having a diameter of 5 cm and a thickness of 1 cm heated to
800.degree. C. was placed on the surface leveled evenly to burn the
grease composition. After 10 seconds, the metal piece was removed,
and the time until the fire on the grease composition was
completely extinguished after removing the metal piece was
measured.
<Fuming>
[0110] The presence or absence of fuming was evaluated at the same
time of burning the grease composition. The case where white smoke
was observed was designated as "A", and the case where black smoke
was observed was designated as "B".
<Malodor>
[0111] With respect to the grease compositions on which fire was
completely extinguished, after the fire was extinguished, and with
respect to the grease compositions on which fire was not
extinguished, after they were allowed to be burned for 2 minutes
after the metal piece was removed, and then the fire was forcibly
extinguished, an extent of malodor was determined. Seven persons
attended the test. The composition where five or more persons rated
as no malodor was designated as "A", the composition where three
and four persons rated as no malodor was designated as "B", and the
composition where two persons or less rated as no malodor was
designated as "C".
<Liquefaction>
[0112] With respect to the grease compositions on which fire was
completely extinguished, after the fire was extinguished, and with
respect to the grease compositions on which fire was not
extinguished, after they were allowed to be burned for 2 minutes
after the metal piece was removed, and then the file was forcibly
extinguished, appearance and shape of the grease composition were
evaluated visually. The grease composition whose shape was
maintained without being liquefied was designated as "A", and the
grease composition liquefied was designated as "C".
1-3. Lubricity (Shell Four-Ball Load Resistance Test)
[0113] A fusion load (WL value, unit N) was measured according to
ASTM D2783-03 (2014) under conditions of a rotational speed of
1,760 rpm, 10 seconds, and room temperature. It can be said that
the larger these values are, the better lubricity in a high load
environment is. Those having a measurement value of 1,236 or more,
less than 1,236 and 981 or more, and less than 981 were designated
as A, B, and C, respectively.
1-4. Water Content
[0114] A water content of the grease composition was measured
according to a Karl Fischer titration method of JIS K2275:
1996.
1-5. Sulfur Content
[0115] A sulfur atom content of the grease composition was measured
according to ASTM D4951.
2. Raw Materials
[0116] Details of raw materials (base oil 1, base oil 2, base oil
3, aluminum hydroxide (C1), zinc carbonate (D1), and polyhydric
alcohol (D2)) shown in Tables 1 and 2 and a step for preparing
grease to be described later are as follows. [0117] Base oil 1: A
base oil obtained by distilling residual oil after normal pressure
distillation of paraffinic crude oil under reduced pressure and
dewaxing, deasphalting, and hydrofining the obtained
reduced-pressure distillation residue oil. [Bright stock (A1-a),
40.degree. C. kinematic viscosity: 408.8 mm.sup.2/s, viscosity
index: 107, sulfur content: 2 ppm by mass, initial boiling point:
465.degree. C., flash point: 300.degree. C.] [0118] Base oil 2: A
base oil obtained by distilling residual oil after normal pressure
distillation of paraffinic crude oil under reduced pressure and
dewaxing, deasphalting, and hydrofining the obtained
reduced-pressure distilled oil. [500 N of mineral oil, 40.degree.
C. kinematic viscosity: 90.5 mm.sup.2/s, viscosity index: 103,
sulfur content: 3 ppm by mass, initial boiling point: 336.degree.
C., flash point: 250.degree. C.] [0119] Base oil 3: A base oil
obtained by distilling residual oil after normal pressure
distillation of paraffinic crude oil under reduced pressure and
dewaxing, deasphalting, hydrofinishing, and solvent-extracting the
obtained reduced-pressure distillation residue oil. [Bright stock
(A1-b), 40.degree. C. kinematic viscosity: 435.1 mm.sup.2/s,
viscosity index: 107, sulfur content: 10,200 ppm by mass, initial
boiling point: 355.degree. C., flash point: 330.degree. C.] [0120]
Aluminum hydroxide (C1): manufactured by FUJIFILM Wako Pure
Chemical Corporation, purity: 95%, average particle diameter: 1
.mu.m-1,3,5-triazine-1,3,5 (2H, 4H, 6H)-tris(ethanol) (C2):
manufactured by Maruzen Petrochemical [0121] Zinc carbonate (D1):
Basic zinc carbonate, manufactured by FUJIFILM Wako Pure Chemical
Corporation, purity: 69.0% to 74.0% [0122] Polyhydric alcohol (D2):
Glycerin, manufactured by FUJIFILM Wako Pure Chemical Corporation,
purity: 97% [0123] Calcium hydroxide: manufactured by FUJIFILM Wako
Pure Chemical Corporation, purity: 96% [0124] Magnesium hydroxide:
manufactured by FUJIFILM Wako Pure Chemical Corporation, purity:
96%
3. Preparation of Lithium Complex Soap Grease and Lithium Soap
Grease
[0125] Lithium complex soap greases 1 to 3 and lithium soap greases
1 to 2 serving as a base for the grease compositions of Examples 1
to 11 and Comparative Examples 1 to 9 were prepared.
3-1. Lithium Complex Soap Grease 1
[0126] (i) The base oil 1 (an amount of 1/2 of the amount described
in Tables 1 and 2), 2.7 mass % of 12-hydroxy stearic acid, and 3.4
mass % of azelaic acid were charged into a grease producing kettle,
and the mixture was heated and dissolved while stirring. [0127]
(ii) An aqueous solution in which 2.0 mass % of lithium hydroxide
(monohydrate) was dissolved was added to the above (i). The mixture
was heated and mixed until the temperature of the grease reached
192.degree. C., and then held for 5 minutes. (iii) The extreme
pressure agent (zinc dialkyl dithiophosphate) was added and cooled
to 140.degree. C., then a remaining amount (an amount of 1/2 of the
amount described in Tables 1 and 2) of the base oil 1 was added,
placed in an environment of 50.degree. C. for one hour and cooled
to 100.degree. C. to obtain a lithium complex soap grease 1.
3-2. Lithium Complex Soap Grease 2
[0128] A lithium complex soap grease 2 was obtained in the same
manner as in the preparation of the lithium complex soap grease 1
except that the base oil 1 was changed to the base oil 2.
3-3. Lithium Complex Soap Grease 3
[0129] A lithium complex soap grease 3 was obtained in the same
manner as in the preparation of the lithium complex soap grease 1
except that the base oil 1 was changed to the base oil 3.
3-4. Lithium Soap Grease 1
[0130] (i) The base oil 1 (an amount of 1/2 of the amount described
in Table 1) and 5.8 mass % of 12-hydroxy stearic acid were charged
into a grease producing kettle, and the mixture was heated and
dissolved while stirring. [0131] (ii) An aqueous solution in which
0.9 mass % of lithium hydroxide (monohydrate) was dissolved was
added to the above (i), and the mixture was heated and mixed. When
a temperature of grease reached 140.degree. C., 0.3 mass % of zinc
stearate was added, and the mixture was further heated and mixed.
The temperature of grease reached 197.degree. C., and then was held
for 5 minutes. [0132] (iii) Next, the remaining amount (an amount
of 1/2 of the amount described in Table 1) of the base oil 1 was
added, the mixture was placed in an environment of 50.degree. C.
for one hour and cooled to 80.degree. C., and then an amine-based
antioxidant was added and mixed therewith. [0133] (iv) Further, the
mixture was allowed to be naturally cooled to room temperature to
obtain a lithium soap grease 1.
3-5. Lithium Soap Grease 2
[0134] A lithium soap grease 2 was obtained in the same manner as
in the preparation of the lithium soap grease 1 except that the
base oil 1 was changed to the base oil 2.
4. Preparation and Arrangement of Grease Composition
[0135] A fire retardant and a fire retardant promotor, and the like
described in Tables 1 and 2 were added to the lithium complex soap
grease or the lithium soap grease described in Tables 1 and 2, and
a finishing treatment was performed using a three-roll apparatus to
obtain each of the grease compositions of Examples 1 to 11 and
Comparative Examples 1 to 9.
[0136] Further, a commercially available grease composition
(manufactured by Kyodo Yushi, trade name: FR grease L No.1,
thickener: lithium soap, containing sulfur-based compound) was got
as the grease composition of Comparative Example 10.
TABLE-US-00001 TABLE 1 Examples 1 2 3 4 5 6 Composition Lithium
complex Base oil 1 [Base oil (A1)] Remainder Remainder Remainder
Remainder Remainder Remainder (mass %) soap grease 1 Lithium
complex soap 6.7 6.7 6.7 6.7 6.7 6.7 [Thickener (B)] ZnDTP 1.7 1.7
1.7 1.7 1.7 1.7 Lithium soap Base oil 1 [Base oil (A1)] -- -- -- --
-- -- grease 1 Lithium soap [Thickener (B)] -- -- -- -- -- --
Amine-based antioxidant -- -- -- -- -- -- Fire retardant (C)
Aluminum hydroxide (C1) 5.0 4.0 4.0 4.0 -- 1.0 1,3,5-triazine-1,3,5
-- -- -- -- 4.0 -- (2H, 4H, 6H)-tris(ethanol) (C2) Fire retardant
Zinc carbonate (D1) -- -- -- 2.0 2.0 -- promotor (D) Polyhydric
alcohol (D2) -- -- 3.0 -- -- -- Other additives Calcium hydroxide
-- -- -- -- -- -- Magnesium hydroxide -- -- -- -- -- -- Properties
Water content (mass %) 0.01> 0.01> 0.01> 0.01> 0.01>
0.01> Sulfur content (mass %) 0.01> 0.01> 0.01>
0.01> 0.01> 0.01> Evaluation Fire extinguishing
performance (seconds) 12 20 7 9 31 25 Fuming A A A A A A Malodor A
A A A A A Liquefaction A A A A A A Lubricity (WL) A A A A A A
Examples 7 8 9 10 11 Composition Lithium complex Base oil 1 [Base
oil (A1)] Remainder Remainder Remainder Remainder -- (mass %) soap
grease 1 Lithium complex soap 6.7 6.7 6.7 6.7 -- [Thickener (B)]
ZnDTP 1.7 1.7 1.7 1.7 -- Lithium soap Base oil 1 [Base oil (A1)] --
-- -- -- Remainder grease 1 Lithium soap [Thickener (B)] -- -- --
-- 6.7 Amine-based antioxidant -- -- -- -- 1.7 Fire retardant (C)
Aluminum hydroxide (C1) 10.0 3.0 -- 3.0 5.0 1,3,5-triazine-1,3,5 --
2.0 3.0 3.0 -- (2H, 4H, 6H)-tris(ethanol) (C2) Fire retardant Zinc
carbonate (D1) -- -- 3.0 3.0 -- promotor (D) Polyhydric alcohol
(D2) -- -- -- 3.0 -- Other additives Calcium hydroxide -- -- -- --
-- Magnesium hydroxide -- -- -- -- -- Properties Water content
(mass %) 0.01> 0.01> 0.01> 0.01> 0.01> Sulfur
content (mass %) 0.01> 0.01> 0.01> 0.01> 0.01>
Evaluation Fire extinguishing performance (seconds) 10 18 32 15 10
Fuming A A A A A Malodor A A A A A Liquefaction A A A A A Lubricity
(WL) A A A A A
TABLE-US-00002 TABLE 2 Comparative Examples 1 2 3 4 5 6 Composition
Lithium complex Base oil 1 [Base oil (A1)] Remainder Remainder
Remainder Remainder Remainder -- (mass %) soap grease 1 Lithium
complex 6.7 6.7 6.7 6.7 6.7 -- soap [Thickener (B)] ZnDTP 1.7 1.7
1.7 1.7 1.7 -- Lithium complex Base oil 2 -- -- -- -- -- Remainder
soap grease 2 Lithium complex -- -- -- -- -- 6.7 soap [Thickener
(B)] ZnDTP -- -- -- -- -- 1.7 Lithium complex Base oil 3 -- -- --
-- -- -- soap grease 3 Lithium complex -- -- -- -- -- -- soap
[Thickener (B)] ZnDTP -- -- -- -- -- -- Lithium soap Base oil 2 --
-- -- -- -- -- grease 2 Lithium soap [Thickener (B)] -- -- -- -- --
-- Amine-based antioxidant -- -- -- -- -- -- Fire retardant (C)
Aluminum hydroxide 0.5 15.0 -- -- -- 5.0 1,3,5-triazine-1,3,5 -- --
-- -- -- -- (2H, 4H, 6H)-tris(ethanol) (C2) Fire retardant Zinc
carbonate (D1) -- -- -- -- 3.0 -- promotor (D) Polyhydric alcohol
(D2) -- -- -- -- -- -- Other additives Calcium hydroxide -- -- 5.0
-- -- -- Magnesium hydroxide -- -- -- 5.0 -- -- Properties Water
content (mass %) 0.01> 0.01> 0.01> 0.01> 0.01>
0.01> Sulfur content (mass %) 0.01> 0.01> 0.01>
0.01> 0.01> 0.01> Evaluation Fire extinguishing
performance (seconds) Not 12 35 Not 40 Not extinguished
extinguished extinguished Fuming A A A A A A Malodor A A A A A A
Liquefaction A A A A A A Lubricity (WL) A C B B A B Comparative
Examples 7 8 9 10 Composition Lithium complex Base oil 1 [Base oil
(A1)] -- Remainder -- Commercially (mass %) soap grease 1 Lithium
complex -- 6.7 -- available soap [Thickener (B)] product ZnDTP --
1.7 -- Lithium complex Base oil 2 -- -- -- soap grease 2 Lithium
complex -- -- -- soap [Thickener (B)] ZnDTP -- -- -- Lithium
complex Base oil 3 -- -- Remainder soap grease 3 Lithium complex --
-- 6.7 soap [Thickener (B)] ZnDTP -- -- 1.7 Lithium soap Base oil 2
Remainder -- -- grease 2 Lithium soap [Thickener (B)] 6.7 -- --
Amine-based antioxidant 1.0 -- -- Fire retardant (C) Aluminum
hydroxide 5.0 -- 5.0 1,3,5-triazine-1,3,5 -- 15.0 -- (2H, 4H,
6H)-tris(ethanol) (C2) Fire retardant Zinc carbonate (D1) -- -- --
promotor (D) Polyhydric alcohol (D2) -- -- -- Other additives
Calcium hydroxide -- -- -- Magnesium hydroxide -- -- -- Properties
Water content (mass %) 0.01> 0.01> 0.01> 0.01> Sulfur
content (mass %) 0.01> 0.01> 1.0 1.5 Evaluation Fire
extinguishing performance (seconds) Not 40 23 32 extinguished
Fuming B A A B Malodor A C B C Liquefaction A A A C Lubricity (WL)
B B A B
[0137] From the results of Tables 1 and 2, the grease compositions
of Examples 1 to 11 are excellent in fire extinguishing performance
while water is not contained. Further, it can be confirmed that
fuming, malodor, and liquefaction on burning can be suppressed and
the lubricity is also good.
[0138] On the other hand, the grease compositions of Comparative
Examples 1 and 3 to 5 have a small content of a fire retardant or
contain no fire retardant, and therefore, the fire extinguishing
performance is insufficient, and the flame retardancy is poor. In
the grease compositions of Comparative Examples 2 and 8, the
content of the fire retardant is large, and therefore, they have an
insufficient lubricity or cause malodor. In each of the grease
compositions of Comparative Examples 6 and 7, an initial boiling
point of the base oil is low, and therefore, the fire extinguishing
time is long, and the fire extinguishing performance is poor. In
the grease composition of Comparative Example 9, the sulfur content
of the base oil is large, so that malodor occurs at the time of
burning. Further, in the grease composition of Comparative Example
9, the initial boiling point of the base oil is low, and therefore,
the fire extinguishing time is long, and the fire extinguishing
performance is poor as compared with the grease composition of
Example 1 in which the kind and addition amount of the fire
retardant are the same.
INDUSTRIAL APPLICABILITY
[0139] The grease composition of the present embodiment is
excellent in fire extinguishing performance without water and can
suppress fuming, malodor, and liquefaction on burning. Therefore,
the grease composition of the present embodiment can be suitably
used in various equipment and machines, particularly suitably used
as the grease composition for steel manufacturing equipment,
forging equipment, or a heat treatment apparatus in which fire
extinguishing performance is important.
* * * * *